Treatment of steel and iron surfaces.



W. s. SIMPSON. TREATMENT or STEEL AND IRON SURFACES.

APPLICATION FILED AUG. 1'], 1912. 1,064,67 l Patented June 10, 1913.

3 SHEETS-SHEET 1.

fizuezvZov zl/zillaauw Sake v0 0 2/ W. S. SIMPSON. TREATMENT OF STEEL AND IRON SURFACES.

APPLICATION FILED AUG. 17, 1912.

Patented June 10, 1913.

3 SHEETS-SHEET 2.

fizaeizior wazia'anv 56272 019022 W. S. SIMPSON. TREATMENT OF STEEL AND IRON SURFACES.

APPLICATION FILED AUG. 17, 1912.

. n m a w 0 w m wp IE '1 i Z M m a s h H LP Z d H 7 G m j 7 LM r f n/ flu, I 2,, m a n n m m m m W C C C C C R 2% @n 5 Q Q Q desirable qualities.

' UNITED STATES PATENT OFFICE.

WILLIAM SPEIRS SIMPSON, OF LONDON, ENGLAND.

TBEATHENT O1 STEEL AND IRON SURFACES.

Specification of Letters Patent.

Patented June o, 1913.

tion therein of metals or metallic compounds for hardening, toughening or otherwise improving such surfaces and all without oxidation or deterioration during the process which throughout is carried on in cacao. By this method or process'the plate, bar or other article may be converted into two or more qualities of steel or iron either at the back or front and byaseries of operations may be caused to consist of several layers of metal varying in hardness, ductility or other In no case are the metals or surfaces burned or oxidized but on the" contrary are purified and improved, the ultimate surface when cooled being free from blowholes. For example: in the manufacture of an armor plate my procedure is asfollows: I prepare aplate of suitable size and thickness which (preferably) has been rendered of superior quality as regards tensile strength, toughness, ductility, etc., by reason of its carbon contents and by the employment of suitable metallic alloys as well as by known'methods of forging, rolling, heat treatment, etc. ,I then place this plate in 'a metallic chamber so constructed as to be employed as a vacuum chamber. The plate rests horizontally therein upon a platform or carriage supported on wheels and capable of being moved backward and forward or shifted laterally, without breaking vacuum. In some cases especially in treating thin plates the surface of the platform orcarquate to prevent the escape of any molten metal from the surface of the plate. After the vacuum chamber has been closed and a high vacuum created thereln, electrical h a Application filed August 17, 1912. Serial No. 715,838.

is applied to the face of the plate in such-a A :manner and with such local intensity that any or all parts of the surface are rendered molten either simultaneously or in. sections. The electrodes whereby'such effect is pro- 60 duced are under the perfect control of the op- 'erator and are suflicient in number to render ;effective the heating and super-heating of the surface of the plate to. any depth de- "sirable for the introduction of metallic al- 6'5 loys or improving the character of the steel 1 composing the surface of the plate for certain definite purposes, and although in the early stages of fusing the iron or steel sur-.

j face it is convenient to bring theelectrode l or electrodes into contact with such surface I provide a fusible slag covering therefor which enables the arc to be maintained even if the electrode is raised above the metallic 5 surface and out of actual contacttherewith during the final stages of the operation.

Eben or form-manganese, an increasedper- 8 f eentage of some one or more of the various -;metals already present as alloys, or it may consist in the impregnation of either face of the plate with a suitable alloying metal not @already. present in the steel (such for instance as nickel, chromium, molybdenum, tungsten or vanadium) which may be added i either pure or in combination with iron. A gpre-determined quantity of one or more a1? oyi'ng metals or metallic compounds-may be 9' E placed upon the surface of the plate before the application of the electrical heat, inany gconvenie-nt form suitable for melting and jmixing so that upon being. fused they mayv become a part of the surface of the plate, or 1%00 (in some cases) the metals or metallic cornipounds may be separately prepared and melted and then introduced Within the vacuu'mchamber while in a molten condition and:

3 added to the fused metal already composing Ithe face of the plate. y

In some cases my initial plate may be icomposed of a purequ-ality of iron, rolled i or otherwise into the requisite shape, which,-

by my treatment, may be impregnated as 0 vacuum should be maintained and the higher the vacuum employed the more perfect is the result obtainable; since under such conditions there is no oxidation of the sensitive metals introduced as alloys and no deterioration of the metals or any of them through super-heating. The best results obtainable at present are effected with -ing a number of electrodes.

a vacuum above 27, under barometric conditions of 30, or if the barometric conditions are different, under about-- the same ratio. Moreover the extreme fluidity of the metals obtainable in vacuo facilitates a perfect diffusion and alloy.

In the manufacture of an armor plate this process renders it possible to impregnate the face of the plate to a depth of two or more inches with any alloying metal-,-

especially such metals as molybdenum or tungsten, in suitable proportions to render the steel self-hardeningon exposure to the air, or carbon as .contained in the carbids of iron may be added to the steel surfaces to a much greater depth and in a more uniform manner than by cementation in cases where it is desirable to harden by chilling in water or otherwise.

The apparatus I prefer to employ is shown in the annexed drawings whereof:

Figure 1 is a front elevation with the dome closed and showing the appliance for moving the dome. Fig. 2 is a side sectional elevation showing only the dome-and the carriage and its actuating gear. .Fig. 3 is a part sectional plan of the apparatus showv Fig. 4 is a view similar to Fig. 2, with a modified gear for actuating the carriage and with means for cleaning the sight holes and showing only one electrode in position.

The apparatus shown is designed for the electrical fusion of the surface of comparatively small plates or bars. of iron or steel and the introduction of some hardening material such as carbon, tungsten or other suitable material. 4

The apparatus consists of a base or foundation 1, of trough shape'and containing a pair of rails 2 on which 'areplaced wheels 3-carrying a frame 4, two opposite members of which are provided with rails 5 positioned at right angles to the rails 2. On these rails 5, are mounted wheels 6 carrying the platform or carriage 7. which latter receives or contains the article 8 to be treated.

According to Figs. 1, 2 and 3, the carriage 7 is provided with a rack 9 into which gear toothed wheels 10 on rods 11 provided with hand wheels 12. These rods are positioned in tubes 13 secured at one end to the frame 4:, and said tubes, after passing through stufling boxes 15 in the founda -t-ion 1, are connected by a bar 16 having cording to Fig. 1 by a single rod 11 and tube 13, and in this case a lever 21 is employed which engages by a collar 22, the tube 13, and is connected to the foundation by links 22 so that by operating the lever 21 the carriage 7 and the frame 4 can-be moved in the directionas moved by the screw '20. On this carriage I aflix the article 8 to be treated, such article being positioned in a recess in the carriage and packed in powdered chromite or carbon 35- to prevent the fused metal from flowing off. the surface over the edge. Upon the surface of the said article to be treated are then applied the metals or metallic compounds 36 to be alloyed therewith, and upon these, in turn, is placed the covering of fusible slag 37i On the foundation is positioned a dome 23 which, when oil the foundation is carried by chains 25 running over pulleys on a derrick 26, said derrick running on a track or on the ground to move the dome 23 completely away from the foundation 1.

The dome is provided with sight holes 27 which can be cleaned by the cleaner 28 carried by a rod 29 through a stufling box 30 to the outside.

The electrodes 31 depend from the dome 23 and are of any desired number and connected up with the source of electric supply by flexible wires through switches for establishing the current to any or all of them, and such electrodes are each carried by a screw 32 operable from outside the dome to position the .points of the electrodes at the desired position over the article being treated.

33 are pipes connected with a suction pump for creating the vacuum when the dome 23 is secured to the foundation 1.

The article to be treated is introduced and The object of the suitably packed while the dome is ofl' the vE foundation, and after that the dome is placed on the foundation and the electrodes suitably positioned; then a vacuum is created' and the electric current switched on to the desired electrodes, and as the operation proceeds, the carriage isnioved to ex ose every part of the articleto the action o the electric current..- v

The water foricoolingthe'under surface dome may'be sprayed, with water from a pipe 34 while the operation is in' progress to I keep the dome cool.

sire to secure. by Letters Patent is:

1-. The method, of mpregnating steel= or iron surfaces withlinetal's or metallic nomf pounds for hardening, toughening-or lIIb proving 3 the same, to any de'sire'd depth,

which consists in fusing electrically and alloying such surfaces while in a substantial vacuum.--. v

substantial vacuum.

2. The method f iIn regnatingsteel or iron surfaces with meta s ormetallic coinpounds, for hardening, toughening or.1m-

proving the same, tof any. desired depth,

which consists infusing electrically, alloy} ing and carburizingsuch surfaces while in, a

3. The method of impregnating steel or iron surfaces with foreign matter for hardening, tougheningfor improving. the same,

to a'nydesired depthfiwhich consists inapplying said matter to said surfaces, covering said matter with fusible slag, and-thereafter What I do claim as niy invention and 'de- 7 v I stratum of slag to melt said surfaces and melting said surfaces and matter by means of an electric arc. while in a substantial vacuum, i

4. The method of impregnating steelor iron surfaces with foreign matter. for liar-- dening, toughening .or improving the same,

to any desired depth, which consists in ap'-- plying said matter to said surfaces, covering vsaid matterwith fusible slag, and thereafter springing an electric are through Y the matter, while in'a substantial vacuum, with-- out the electrodes coming into actual contact with the'molten metal. c i

denin'g, toughening and improving metallic surfaces which. involves fusing the sameelectrical-ly while in a substantial vacuum v 1 and superheating such molten surfaces, ".whereby'perfect'diffusion' of the alloys is efiectedand-voccluded gases are liberated froin the molten metalfand withdrawn as liberatedi i 1' In testimonywhereof I have hereunto setmy hand inpresence oftwo'subscribing witnesses.

' \VILLIAM. SPEIBS SIMPSON;

witnessesz' O. J. NORTH,

GRIATT.

5. T he herein described method of har-- 

